1. Field of the Invention
The present invention relates to motorcycle tyres. In particular, the present invention relates to tyres intended to be mounted on the front wheel and/or on the rear wheel of “enduro street” motorcycles with a medium to large engine capacity (for example 700-1000 cm3 or more) and/or high power (for example about 100 hp or more).
2. Description of Related Art
Recently there has been a tendency to introduce onto the market “enduro street” motorcycles which are intended for mixed use both on roads and off-the-road and which have an increasingly higher greater capacity and/or power. In fact, there are already present on the market, for example, enduro motorcycles with an engine capacity of 1250 cm3 and power of about 100 hp.
The tyres mounted on the wheels of these motorcycles must ensure a stable behaviour both on ordinary roads and along mountain roads which have a large number of bends and even in cross-country terrain, together with the capacity to travel a large number of kilometers.
Therefore, they must have excellent road-holding and traction properties so as to be able to transmit effectively to the ground the high driving torque on widely varying terrain and also ensure an effective braking action. Grip and traction also assume critical importance in wet road and off-the-road travel conditions.
These tyres must, moreover, ensure stability and comfort during roadway travel as well as a fairly high level of performance and grip, in particular when accelerating out of bends.
Obtaining all of the above-mentioned characteristics appears to be particularly difficult, partly because of the conflicting nature of these characteristics, in particular in the case of motorcycle tyres which must be able to cope with such varied travel conditions.
U.S. Pat. No. 4,364,426 describes a motorcycle tyre having a tread provided with a plurality of spaced blocks defined by a plurality of first circumferentially spaced grooves which extend substantially diagonally across the tread. The first grooves channel the water from the centre of the tread and extend continuously one side to the other of the tread. Each first groove has moreover a middle portion which extends substantially circumferentially. The middle portions of two adjacent first grooves are spaced by a block defined by first adjacent grooves.
JP61092903 describes a tyre for “enduro on-off” motorcycles designed to ensure uniformity of contact by providing on the tread band a plurality of blocks arranged in the circumferential direction of the tyre. The top edge of at least one side of the blocks is designed so as to be positioned along both the side edges of the tread band, projecting outwards from the contour of the central portion of the tread.